
\begin{tikzpicture}[scale=1.5]
  \tkzDefPoints{0/0/B,2/0/A}
  \tkzInterCC[R](A,3)(B,4)     \tkzGetSecondPoint{C}
  \tkzDefLine[altitude](A,C,B) \tkzGetPoint{H}
  \tkzDrawPolygon(A,B,C)
  \tkzDrawSegments(C,H A,H)
  \tkzMarkRightAngle(C,H,B)
  \tkzDrawPoints(A,B,C,H)
  \tkzLabelPoints[below](A,B,H)
  \tkzLabelPoints[above](C)
\end{tikzpicture}
